In a large skillet, heat the olive oil and butter together. Add the leeks, fennel, salt and pepper and saute, over medium heat for about 5 or 6 minutes, until the vegetables are softened. Add the garlic and saute one minute more. Transfer to a large bowl.

Make the sauce:In a medium saucepan, melt the butter and add the flour, stirring with a whisk. Cook the flour for a couple of minutes and add the bouillon cube, whisking til it dissolves. Slowly add in the milk, whisking. Add the nutmeg, sea salt and pepper. Whisk until sauce is creamy and thick. Add the Sherry. Turn off heat and add the cheese.

Add the sauce to the vegetables in the bowl and mix well together. Add the seafood and artichoke and mix gently. Pour into a baking dish (3-quart is a good size).

Mix the chopped parsley, bread crumbs and cheese together in a small bowl. Sprinkle over the top of the casserole. Bake at 350 degrees F. for about 25 minutes. Broil the top for about one minute, until it is golden brown.

Serve over rice or noodles. There's lots of broth, so serve some nice crusty bread with it. Leftovers keep well in the fridge and it firms up quite a bit the next day.